I just spent a half hour troubleshooting a problem I’d never seen before.
If you don’t want to read on simply remember to CHECK YOUR COMPUTER FOR THE CORRECT DATE and TIME before you proceed with other ideas.
I was having lots of trouble accessing gmail, getting a cryptic message about an invalid security certificate. Twitter too – in fact chrome was giving the “red alert of death” message that made is seem like Twitter had a virus. Unlikely, but odd.
Assuming this was a cache issue I cleared all that but the problems remained. However I noticed that gmail was fine on another computer and my mobile android phone, so clearly this was a problem with my desktop PC.
I don’t show the date below, only the time, so I’m not even sure how I stumbled on to the fact that I’d managed to change my date accidentally earlier this morning from November to February. Since my browser was working fine I’m still not sure why Google Chrome wasn’t clever enough to warn me that my computer was out of sync with the real time, but instead of that it appears Chrome simply assumed my computer time was CORRECT and the security certificates for logging in at Gmail and Twitter were bogus or dangerous.
In any case, CHECK YOUR DATE when troubleshooting login problems.